1. Field of the Invention
The present invention relates to a scouring pad device and a method for making the device. More particularly, the present invention relates to a scouring pad device that contains a cleaning or polishing composition which is released at a controlled rate over an extended period of time.
The present invention also relates to a method of making scouring pad devices that employs heat or ultrasonic welding technology to achieve mass production efficiencies.
2. Description of the Prior Art
Scouring pad devices are typically used in commerical, institutional, and consumer applications to clean cooking utensils such as aluminum, stainless steel and copper pots and pans. Most widely known scouring pad devices include a pad of steel wool. A soap or a polishing composition, which is soluble in water, is carried in the interstices between fibers of the steel wool. Accordingly, when the pad is immersed in water, the cleaning composition dissolves and is carried to the surfaces of the pad. Motion of the pad over the surface of the utensil then cleans and polishes the utensil.
Such commonly used scouring pad devices have inherent drawbacks. Most notably, since the soap or polish composition is merely held in the readily accessible interstices between adjacent fibers of the steel wool, it may be dissolved and carried away from the pad in a relatively short period of time. Additionally, the steel wool with which the pad is made can oxidize or rust and in fact does so rapidly after it has been immersed in water for the first time.
Attempts have been made to solve certain of the drawbacks of such commonly used scouring pad devices. Most notably, fiberous polymeric materials which are non-woven or randomly spun into a pad that is joined randomly together to maintain the integrity of the pad, and synthetic and natural sponge-like materials have been substituted for steel wool and other like metalic materials. Again, however, soap or polishing compositions are commonly impregnated or carried in the interstices in the sponge or between adjacent fibers of the polymeric material in much the same fashion as are such compositions in steel wool scouring pads. Accordingly, while the problem of oxidization of the pad itself is avoided with polymeric and naturally corrosion resistant pad materials, the problem of rapid use of the soap or polish composition still remains.
Variation of the polymeric scouring pad device are also known. For example, materials having different hardnesses and, therefore, different abrasive qualities may be laminated together. In this way, one surface of the device may resent a mildly abrasive surface for scouring while an opposite surface of the device can provide a more coarsely abrasive surface. Again, however, in such devices, soap or polish composition is merely impregnated or carried in the interstices between fibers of the polymeric material from which the device is made. Thus, prior art devices provide no control over the rate at which the soap composition is released.
Mass production techniques using ultrasonic or heat-welding have been developed in the past for making products for dispensing volatile substances such as perfumes and deodorizers. For example, U.S. Pat. No. 4,094,119 (Sullivan) discloses such a process. However, use of such techniques for manufacturing scouring pad devices that release a soap or polishign composition at a controlled rate over an extended period of time are not believed to have been known in the prior art.